PRLR (Prolactin Receptor): PRLR is a receptor that binds to the hormone prolactin, which plays a role in milk production, reproductive functions, and immune regulation. When prolactin binds, PRLR activates signalling pathways that control cell growth, development, and differentiation. Dysregulation of PRLR signalling has been associated with breast and other cancers, highlighting its role in cellular proliferation and its potential as a therapeutic target.